''LiteBIRD'' (''Lite (Light) satellite for the studies of B-mode polarization and Inflation from cosmic background Radiation Detection'') is a planned small space observatory that aims to detect the footprint of the primordial gravitational wave on the

cosmic microwave background In Big Bang cosmology the cosmic microwave background (CMB, CMBR) is electromagnetic radiation that is a remnant from an early stage of the universe, also known as "relic radiation". The CMB is faint cosmic background radiation filling all spac ...

(CMB) in a form of polarization pattern called B-mode. ''LiteBIRD'' and

OKEANOS OKEANOS (Oversize Kite-craft for Exploration and Astronautics in the Outer Solar system) was a proposed mission concept to Trojan asteroids, which share Jupiter's orbit, using a hybrid solar sail for propulsion; the sail was planned to be cove ...

were the two finalists for Japan's second Large-Class Mission.INVESTIGATION OF THE SOLAR SYSTEM DISK STRUCTURE DURING THE CRUISING PHASE OF THE SOLAR POWER SAIL MISSION.
(PDF). T. Iwata, T. Okada, S. Matsuura, K. Tsumura, H. Yano, T. Hirai, A. Matsuoka, R. Nomura, D. Yonetoku, T. Mihara, Y. Kebukawa, M. ito, M. Yoshikawa, J. Matsu-moto, T. Chujo, and O. Mori. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). In May 2019, LiteBIRD was selected by the

Japanese space agency The is the Japanese national air and space agency. Through the merger of three previously independent organizations, JAXA was formed on 1 October 2003. JAXA is responsible for research, technology development and launch of satellites into orb ...

. ''LiteBIRD'' is planned to be launched in 2028 with an

H3 launch vehicle The H3 Launch Vehicle is an expendable launch system in development in Japan. H3 launch vehicles are liquid-propellant rockets with strap-on solid rocket boosters and are planned to be launched from Tanegashima Space Center in Japan. Mitsub ...

for three years of observations at the Sun-Earth

Lagrangian point In celestial mechanics, the Lagrange points (; also Lagrangian points or libration points) are points of equilibrium for small-mass objects under the influence of two massive orbiting bodies. Mathematically, this involves the solution of th ...

L2.

Overview

Cosmological inflation In physical cosmology, cosmic inflation, cosmological inflation, or just inflation, is a theory of exponential expansion of space in the early universe. The inflationary epoch lasted from seconds after the conjectured Big Bang singularit ...

is the leading theory of the first instant of the

universe The universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy. The Big Bang theory is the prevailing cosmological description of the development of the universe. Acc ...

, called the

Big Bang theory The Big Bang event is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models of the Big Bang explain the evolution of the observable universe from the ...

. Inflation postulates that the universe underwent a period of rapid expansion an instant after its formation, and it provides a convincing explanation for cosmological observations.LiteBird Science
JAZA/ISAS. Accessed 6 October 2018. The primordial gravitational waves are expected to be imprinted in the CMB polarization map as special patterns, called the B-mode. Measurements of polarization of the CMB radiation are considered as the best probe to detect the primordial gravitational waves, that could bring a profound knowledge on how the Universe began, and may open a new era of testing theoretical predictions of

quantum gravity Quantum gravity (QG) is a field of theoretical physics that seeks to describe gravity according to the principles of quantum mechanics; it deals with environments in which neither gravitational nor quantum effects can be ignored, such as in the vi ...

, including those by the

superstring theory Superstring theory is an attempt to explain all of the particles and fundamental forces of nature in one theory by modeling them as vibrations of tiny supersymmetric strings. 'Superstring theory' is a shorthand for supersymmetric string theor ...

. The science goal of ''LiteBIRD'' is to measure the CMB polarization over the entire sky with the sensitivity of δr <0.001, which allows testing the major single-field slow-roll inflation models experimentally.LiteBIRD - Team Members
JAXA/ISAS. Accessed: 8 October 2018.

Telescopes

In order to separate CMB from the galactic emission, the measurements will cover 40 GHz to 400 GHz during a 3-year full sky survey using two telescopes on ''LiteBIRD''. The Low Frequency Telescope (LFT) covers 40 GHz to 235 GHz, and the High Frequency Telescope (HFT) covers 280 GHz to 400 GHz. LFT has a 400 mm aperture Crossed-Dragone telescope, and HFT has a 200 mm aperture on-axis refractor with two silicon lenses. The baseline design considers an array of 2,622 superconducting

polarimetric Polarimetry is the measurement and interpretation of the polarization of transverse waves, most notably electromagnetic waves, such as radio or light waves. Typically polarimetry is done on electromagnetic waves that have traveled through or ...

detectors.LiteBIRD instrumentation
JAXA/ISAS. Accessed: 6 October 2018. The entire optical system will be cooled down to approximately to minimize the thermal emission,

References

External links

LiteBIRD Official home pageLiteBird System Overview
from 2012 {{DEFAULTSORT:LiteBIRD 2028 in spaceflight Proposed spacecraft Satellites of Japan Space telescopes Physical cosmology Cosmic microwave background experiments

Overview

Telescopes

See also

References

External links